https://github.com/google/varstruct

https://github.com/google/varstruct

Last synced: 3 months ago
JSON representation

• Host: GitHub
• URL: https://github.com/google/varstruct
• Owner: google
• License: apache-2.0
• Archived: true
• Created: 2017-03-14T06:25:59.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2017-03-14T08:01:19.000Z (over 7 years ago)
• Last Synced: 2023-04-09T06:27:20.737Z (about 1 year ago)
• Language: C++
• Size: 15.6 KB
• Stars: 16
• Watchers: 5
• Forks: 14
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE

Lists

• awesome-bazel - Varstruct

README

        
# Varstruct Overview

Varstruct creates struct-like types with runtime-computed array sizes.

Varstruct is a header-only library -- if you can't use the included Bazel-based

build config, just add varstruct.h and varstruct_internal.h to your includes.

C-style struct definitions may have internal array fields; however, these field

declarations must specify the size of each array at compile time so that the

compiler may reserve enough space when computing the offset of each member and

the size of the struct.

Unfortunately, many I/O protocols use headers with internal arrays whose size is

specified or computed based on other header fields. Therefore, code that parses

these headers often has to perform error-prone manual pointer manipulation.

Varstruct is a C++11 library that creates types that may contains internal

arrays, and the sizes of these arrays may be passed in at runtime. Varstruct

then computes offsets to each member, and can also read and modify fields when

given an input pointer.

(Modification is performed via std::memcpy() to avoid memory alignment problems

that would otherwise occur accessing misaligned fields -- Varstruct doesn't add

any padding of its own).

You can run the tests by running the following in the repo root directory (you

will need Google Bazel installed):

bazel test :varstruct_test

See the comments in varstruct.h for more information.

Author: Caleb Raitto

# Disclaimer

This is not an official Google product.